curl --request PATCH \
  --url https://clarus-api.com/api/external_entities/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-Clarus-Subdomain: <api-key>' \
  --data '
{
  "data": {
    "type": "external_entities",
    "attributes": {
      "description": "Red Widget (large)"
    }
  }
}
'

{
  "id": 501,
  "entity_type": "product",
  "code": "SHOP-SKU-1",
  "description": "Red Widget (large)",
  "external_system_reference1": "gid://shopify/Product/123",
  "external_system_reference2": null,
  "external_system_reference3": null,
  "integration_id": 12
}